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					                    STANFORD UNIVERSITY
                                  MARK Z. JACOBSON
                           Professor of Civil & Environmental Engineering
                       Professor of Energy Resources Engineering, by Courtesy
                                Director, Atmosphere/Energy Program
                       Senior Fellow, Wood Institute for the Environment, by Courtesy

        Department of Civil & Environmental Engineering                   Tel: 650-723-6836
        Yang & Yamazaki Environment & Energy Building                     Fax:650-725-9720
        473 Via Ortega, Room 397                                      jacobson@stanford.edu
        Stanford, CA 94305-4020                        www.stanford.edu/group/efmh/jacobson


     Review of Solutions to Global Warming, Air
           Pollution, and Energy Security
                           Briefing to Senator Jeff Bingaman
               Chairman, Senate Energy and Natural Resources Committee

                  Yang and Yamazaki Environment and Energy Building
                                 Stanford University
                                   October 8, 2008
Thank you, Senator Bingaman, for meeting with us today. I would like to discuss a
review of proposed solutions to global warming, air pollution mortality, and energy
security that is the culmination of several years of work. I have handed out a draft copy of
the review, which contains the calculations referred to here in an appendix, and some
slides. The review considers the proposed solutions with respect not only to climate,
pollution, and energy security, but also to water supply, land use, wildlife, resource
availability, thermal pollution, water pollution, nuclear proliferation, and reliability.
        Nine electric power sources and two liquid fuel options were considered. The
electricity sources included solar-photovoltaics (PVs), concentrated solar power (CSP),
wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and
storage (CCS) technology. The liquid fuel options included corn-E85 and cellulosic E85.
To place the electric and liquid fuel sources on an equal footing, I examined their
comparative abilities to address the problems mentioned above by powering new-
technology vehicles, including battery-electric vehicles (BEVs), hydrogen fuel cell
vehicles (HFCVs), and flex-fuel vehicles run on E85.
        Twelve combinations of energy sources and vehicle type were considered. Upon
ranking and weighting each combination with respect to each of 11 impact categories,
four clear divisions of ranking, or tiers, emerged. Tier 1 (highest-ranked) included wind-
BEVs and wind-HFCVs. Tier 2 included CSP-BEVs, Geothermal-BEVs, PV-BEVs,
tidal-BEVs, and wave-BEVs. Tier 3 included hydro-BEVs, nuclear-BEVs, and CCS-
BEVs. Tier 4 included corn- and cellulosic-E85.
        Wind-BEVs ranked first (best) in seven out of 11 categories, including mortality,
climate damage reduction, footprint on the ground, water consumption, effects on
wildlife, thermal pollution, and water chemical pollution. In fact, the U.S. in 2007 could
theoretically replace all onroad vehicles with BEVs powered by electricity from 73,000-
144,000 5-MW wind turbines operating in 7-8.5 m/s mean wind speeds. This number of
turbines is less than the 300,000 airplanes the U.S. produced during World War II. Such
wind-BEVs could reduce U.S. CO2 by 32.5-32.7% and nearly eliminate 15,000 onroad
gasoline vehicle-related air pollution deaths per year in the U.S. projected in 2020 (a
reduction from about 20,000/yr today). The footprint area of wind-BEVs is 500,000-1
million times less than that of producing ethanol for E85 regardless of whether ethanol is
from corn or prairie grass, 10,000 times less than those of CSP-BEVs or PV-BEVs, 1000
times less than those of nuclear- or coal-BEVs, and 100-500 times less than those of
geothermal, tidal, or wave BEVs. Because of their low footprint and pollution, wind-
BEVs cause the least wildlife loss as well, accounting for bird fatalities.
        Although HFCVs are less efficient than BEVs, wind-HFCVs provide a greater
benefit than any other vehicle technology aside from wind-BEVs. Wind-HFCVs are also
the most reliable combination due to the low downtime of wind turbines, the distributed
nature of turbines, and the ability of wind’s energy to be stored in hydrogen over time.
       The Tier 2 combinations (CSP-, Geothermal-, PV-, tidal-, and wave-BEVs) all
provide outstanding benefits with respect to climate and mortality and are also
recommended. Among Tier 2 combinations, CSP-BEVs result in the lowest carbon
emissions and mortality. Geothermal-BEVs requires the lowest array spacing among all
options examined. Although PV-BEVs result in slightly less climate benefit than CSP-
BEVs, the resource available for PVs is the largest among all technologies considered.
Further, many PVs can be implemented unobtrusively on rooftops. Underwater tidal-
BEVs are the least likely to be disrupted by terrorism or severe weather.
        Tier 3 options (hydro-, nuclear-, and coal-CCS-BEVs) are less desirable.
However, hydroelectricity, which was ranked ahead of coal-CCS and nuclear with
respect to climate- and health-relevant emissions, is an excellent load balancer, thus
recommended. Nuclear and coal-CCS are not recommended since they emit significantly
more carbon and air pollutants than the Tier 1 and Tier 2 options or hydroelectricity, and
the large-scale spread of nuclear energy poses a nuclear weapons security threat to all
nations, as illustrated shortly.
        Specifically, coal, with CCS (and its 85-90% reduction in coal-plant exhaust
emissions), puts out about 77-110 times more lifecycle carbon and other pollutants per
kWh than wind energy. Coal-CCS emissions are primarily from the mining and transport
of coal, exhaust that escapes the CCS equipment, the greater time-lag between the
planning and implementation of a coal-CCS plant that from a wind, solar, or geothermal
plant, and potential leakage from underground storage reservoirs. Further, the addition of
CCS equipment to a coal power plant requires an additional 14-25% energy for coal-
based integrated gasification combined cycle (IGCC) systems and 24-40% for
supercritical pulverized coal plants according to the Intergovernmental Panel on Climate
Change. Such equipment also does not capture health-damaging pollutants, such as NOx,
NH3, and SOx.
        Nuclear power puts out about 24 times more lifecycle carbon and other pollutants
per kWh than wind energy. For nuclear, carbon emissions include those due to the mining
and transport of uranium, the opportunity-cost emissions due to the time-lag between
planning and operation of a nuclear power plant (10-19 years), and the risk (between 0
and 1) of carbon emissions due to the burning of cities associated with nuclear war or
terrorism that is linked to the future increase of nuclear fuel production in nuclear power
plants worldwide. For example, the explosion of 1.5 MT of nuclear weapons material, or
0.1% of the yields proposed for a full-scale nuclear war, during a limited nuclear
exchange or a terrorist attack in a megacity would burn 63-313 Tg of fuel in city
infrastructure, adding CO2 and 1-5 Tg of soot to the atmosphere, much of it to the
stratosphere, and killing 3-17 million people based on a recent paper (Toon et al.).
        As stated in a Los Alamos Report in August 1981, “There is no technical
demarcation between the military and civilian reactor and there never was one.”
Currently, 42 countries have fissionable material to produce weapons; 22 of these
countries have facilities in nuclear energy plants to produce enriched uranium or to
separate plutonium; 13 of these countries are active in producing enriched uranium or
separating plutonium; 9 of these countries have nuclear stockpiles. Having a nuclear
reactor facilitates the basis for obtaining uranium that can then be used either for energy
production and either secretly or openly for weapons production. The U.S. would need to
add 200-275 850 MW nuclear power plants to power all U.S. electric vehicles, and once
the U.S. started to do this, most countries of the world would try to follow, increasing the
risk of nuclear weapons proliferation. Any solution to global warming, air pollution, and
energy security on a large scale must involve technology that can be disseminated
worldwide. As such, this technology cannot be nuclear. If the U.S. uses alone nuclear,
this will undercut international efforts to slow global warming and air pollution mortality.
        The Tier-4 combinations, cellulosic- and corn-E85, were ranked lowest overall
and with respect to climate, air pollution, land use, wildlife damage, and chemical waste.
Cellulosic-E85 ranked lower than corn-E85 overall, primarily due to its potentially larger
land footprint based on new data and its higher upstream air pollution emissions than
corn-E85. Whereas cellulosic-E85 may cause the greatest average human mortality,
nuclear-BEVs may cause the greatest upper-limit mortality risk as discussed above. The
largest consumer of water is corn-E85. The smallest are wind-, tidal-, and wave-BEVs.
        An important issue to address with respect to wind, solar, and wave power is
intermittency. Intermittency can be reduced in several ways, including (1)
interconnecting geographically-disperse intermittent sources through the transmission
system, (2) combining different intermittent sources (wind, solar, hydro, geothermal,
tidal, and wave) to smooth out loads, using hydro to provide peaking and load balancing,
(3) using smart meters to provide electric power to electric vehicles at optimal times, (4)
storing wind energy in hydrogen, batteries, pumped hydroelectric power, compressed air,
or a thermal storage medium, and (5) forecasting weather to improve grid planning.
Currently, the greatest limitation to the large-scale implementation of new, clean electric
power plants is limited transmission line availability.
         In sum, the use of wind, concentrated solar, geothermal, tidal, photovoltaics,
wave, and hydroelectric to provide electricity for BEVs and HFCVs will result in the
most benefit and least impact among the options considered. Coal-CCS, nuclear, corn-
E85, and cellulosic-E85 put out much more carbon and health-damaging pollutants than
the other options examined. Thus, the investment in corn- or cellulosic ethanol, coal-
CCS, or nuclear at the expense of the others will cause certain climate and health
damage, thus economic damage. Because sufficient clean natural resources (wind,
sunlight, hot water, ocean energy, gravitational energy) exists to power all energy for the
world, our failure to focus on these resources by diverting our attention to less efficient or
non-efficient options will guarantee that the significant environmental and energy
problems we face today will not be solved any time soon. The philosophy, that we should
try a little bit of everything is wrong. We need to focus on the technologies that provide
the best benefit. We know which technologies these are.
        Finally, the relative ranking of each electricity option for powering BEVs also
applies to the electricity source when used to provide electricity for general purposes. The
implementation of the recommended electricity options for providing vehicle and general
electricity requires organization. Ideally, good locations of energy resources would be
sited in advance and developed simultaneously with an interconnected transmission
system. This requires cooperation at multiple levels of government.

				
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